Using compressible fluids, especially expanding hot gas or steam, to produce useful work is generally a procedure of heating the gas and then extracting energy of the resulting pressure-volume energy change of expansion to produce external work, with this process involving a flow of heat into and out of the system and thereby being irreversible, and having a relatively low efficiency as described by the Carnot Cycle in the theory of heat exchange in a non-isentropic thermodynamic process [Ref. 1]. The Carnot efficiency is given by the formulaEff.=1−T/To=ΔT/To where T is the gas temperature at the end of the cycle and To is the reference temperature before heat input at the beginning of the Carnot work cycle [1,2]. The source of the heating in a heat engine is usually fossil fuel, so that undesirable or noxious gases are generated and exhausted to the atmosphere.
Devices for transforming internal energy of the air into work by creating kinetic energy of linear air flow, rather than energy of volume expansion or contraction, are less useful and less numerous, for example, vacuum pumps, vacuum cleaners, air blowers and so on. These flow devices are typically inefficient; a typical vacuum cleaner, for example, may be less than 40% efficient.
No previously known device has been self-sustaining, that is to say, has its power output exceeding the power input needed to sustain the basic air flow through the device. It will be seen that the present invention, however, if practiced at close to 100% flow efficiency does accomplish this by an excess of output power over input power. While the present power excess is not large, the new principle established in this invention can lead to large stand-alone power sources or prime movers. Since the present isentropic flow invention is not a heat engine, it does not involve the prohibition against self-sustaining motion by the second law of thermodynamics.
Windmills are another example of air motors [1] in which an essentially linear air flow from wind is used to drive a freely rotating propeller which in turn is attached to a shaft driving an electric generator or motor. The so-called Betz Limit then sets 59.3% as the maximum percentage of wind kinetic energy that can be extracted from the moving air stream by any propeller or turbine. Other losses such as friction, power take-off transfer losses, etc, are in addition to this Betz Limit loss. However, considering that the total internal energy of a mass of air at sea-level conditions (20 degrees C. and 101.3 kilopascals pressure) is very large, the search for a means for a) generating a larger flow velocity and b) then efficiently extracting this new kinetic energy from the flow to do work, was seen by the present inventor as a worthwhile endeavor.
A deterrent to this search lies in the fact that, while the enormous potential energy of this internal heat reservoir of any gas at ordinary temperatures has long been well known, the prudent warnings that any ‘perpetual motion’ even of the “second kind’ from tapping into internal heat energy is still impossible [5] has inadvertently discouraged the inclination to look in the direction of fluid flows for a solution to the world's urgent clean energy needs.
However, the present inventor personally observed on Sep. 2, 1987 [4] a very rare naturally occurring transformation of the internal energy of the atmosphere taking place and producing a small, localized, high speed whirlwind over a calm, cool lake. A lengthy investigation into the thermodynamics of these rare whirlwinds has led the inventor to the conclusion that the process involved is a highly efficient, localized, isentropic transformation of internal energy into rotational kinetic energy rather than an inefficient expansion Carnot cycle or heat engine phenomenon, and, moreover, that this efficient process may be involved in the formative stages of most other whirlwinds such as tornadoes and waterspouts which are much more common.
The inventor was then led to undertake a lengthy investigation into linear isentropic air transformations and to the present invention, which involves the use of such an efficient energy transformation to convert internal energy into kinetic linear flow power, coupled with a novel means for efficiently extracting the enhanced air power reactively as rotational energy and then exporting it for useful work.